This Phase1, multicenter, first-in-human, open-label, dose-escalation, and dose expansion study will evaluate the safety, tolerability, pharmacokinetics, and preliminary anti-tumor efficacy of HLX35 administered as a single-agent by IV infusion every 2 weeks to patients with locally advanced or metastatic solid malignancies, who have failed or are intolerant to standard therapy, or for whom no standard therapy is available. This study has two parts: phase 1a dose escalation and phase 1b dose expansion.

Inclusion Criteria:

• Volunteer to participate in this clinical study; completely understand and know this study as well as sign the informed consent form (ICF);
• Age ≥ 18 years;
• Phase 1a dose escalation: patients must have histologically or cytologically confirmed malignant solid tumors which are advanced or metastatic, have failed prior standard treatment, and be intolerant or ineligible for standard therapy;
• Phase 1b dose expansion: patients must have a histological or cytological diagnosis of Squamous Non-Small Cell Lung Cancer (EGFR H score ≥200 confirmed by central lab) which is advanced or metastatic, have failed prior standard treatment, and be intolerant or ineligible for standard therapy;
• Measurable disease according to RECIST Version 1.1;
• Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1;
• Expected survival 12 weeks;
• Adequate organ function;

Exclusion Criteria:

• Systemic anti-cancer treatment or investigational agents in the 28 days prior to the first study dosing;
• Patients who still have persistent ≥ grade 2 toxicities from prior therapies;
• Active CNS metastasis;
• History of any secondary malignancy in the past 5 years;
• Active autoimmune disease;
• Human immunodeficiency virus (HIV) infection;